I work with two Hungarians. One tells me it is a very rude word. The other (his girlfriend) is not the sort of girl you say very rude things to (unless, I imagine, you are her boyfriend). I've also been working with two Lithuanians. They don't use the word like Poles do - I've only heard it once (not a seemingly infinite number of times as I'm used to). A fellow English colleague of mine has even tried to say it, although he can't roll his Rs.
A friend of mine girlfriend wanted to keep in touh with her after we come back premanently to poland. As I'm a very helpful fella I asked this woman "You want to send text messages to M******?". "Yes, are you OK with it?"... Ouch. It came out as If my girlfriend needed my permission to stay in touch with her friends. :/
I see that once again I made quite a faux pas. I didn't want to say that I don't believe you Osiol. :)
As for the K word, it seemed to be most popular among English chaps actually. They pronounced it something like "koovah match" though. :)